Where to start discussions about cartography?

[Don Nelsen]

You've found what was was once known as "Camp A" on the mainline of the Logging RR.

I think it was Roy Stout who took us in there first, either him or Bus Gibson.

Is this lidar available on-line? dn

The LiDAR data is available on-line but you will need some sort of viewer to use it. What do you use now to view maps and overlay tracks? I might be able to convert the data you want.

Bus took me in there the first time too - he's a great resource on the history of the area. We've done a lot of hiking on Larch and some on the other side of the river too.

All I have is the software that came with my Garmin GPS that I can download to in .gpx form and also my TOPO programs. I use the .tpo files for almost everything. I have no idea how to merge from one program to another or how to merge a track onto a lidar map unless I physically trace it and hand copy it the old primitive way.

don

[Peabody]

Online Lidar viewer

[Adventure Mapper]

Online Lidar viewer

People are sharing valuable information on this thread. Who do we contact to create a new place called "Maps and Navigation" under "Gear and Goodies" as some have proposed?

[Adventure Mapper]

All I have is the software that came with my Garmin GPS that I can download to in .gpx form and also my TOPO programs. I use the .tpo files for almost everything. I have no idea how to merge from one program to another or how to merge a track onto a lidar map unless I physically trace it and hand copy it the old primitive way.
don

I have GIS (Geographic Information Systems) programs that can geo-reference and overlay all types of data. Some are very expensive and some are free. There is a bit of a learning curve on some of them.

I'd like to see if there is a way to make a LiDAR based map using more commonly used tools. The LiDAR data of Larch Mt. that I used was from this USGS site ( http://nationalmap.gov/viewer.html ). It is available in geotiff and 3 other GIS type formats. This is the weak link. I will need to convert the image from geotiff to .kmz so that you can use it in Google Earth.

I propose a test of concept as follows:
- Send me any map of about a square mile. This is just so I can get the extent.
("extent" is a GIS term for the coordinates of a rectangle that includes all of a map.)
- I'll get the LiDAR based image from the National Map.
- I'll convert the LiDAR bare earth hillshade image to .kmz and post it.
- Load the .kmz into Google Earth
- In GE add points and lines at features you see on the LiDAR image
- Export the points and lines as .gpx.
- Load the .gpx into your GPS receiver.
- You should be able to navigate to the features in the real world.

[raven]

If the gpx and kmz files were also loaded into gmap4, custom maps could also be printed and carried.

[Adventure Mapper]

If the gpx and kmz files were also loaded into gmap4, custom maps could also be printed and carried.

I find it helpful to include a UTM grid on the paper map. I use the same grid on my GPS receiver. With this I can locate myself on the paper map quickly. I prefer a paper map over the small one on the GPS receiver because it shows high resolution over a larger area.

[Adventure Mapper]

I was out exploring near Greenleaf Falls last Thursday when the weather was good for a day. We were in some interesting territory and I wanted to examine it in more detail with LiDAR data. Unfortunately LiDAR data was only available for the terrain near the river (I think it was flown right above the middle of the river). In the process of hunting for elevation data I made this image/map that illustrates the difference between typical 10 meter photogrammetry and LiDAR. The grid is 1km. The horizontal resolution of the LiDAR derived elevation data is about 3.5 meters.

The resolution of LiDAR data is usually expressed as points per square meter. I don't know the points per square meter for this data although I could probably find it through the Puget Sound LiDAR consortium.

Notice how road cuts are easily visible. This is "bare earth" data. The tree cover has been effectively removed because the laser pulses penetrate through gaps in the leaves all the way to the ground.

[Adventure Mapper]

There are some hikers who would like to find a source of maps that show property boundaries.

As far as I know this information is not available as what most people think of as a map, i.e., a geo-referenced raster image. It is available as vector information. Vector information is points, lines, and areas, more like the waypoints and tracks such as .gpx and .tpo.

Governments maintain property boundaries, the "cadaster", in their GIS systems. This information is maintained for tax purposes and must be publicly available. In some cases, e.g., Columbia County http://www.co.columbia.or.us/department ... ssors-home, the information is free and on-line. Even if the information is on-line it may not include the owner. There is a court case in California concerning the obligation to make this information available in a complete form rather than requiring the public to view it one parcel at a time. In other counties there is a significant charge and the information usually comes on a DVD. In the worst case you must go to the county offices and look at a paper map. In the Portland area Metro makes taxlot data available through Civic Apps http://www.civicapps.org/.

When you can get property boundary data it will almost certainly not be in any format that I see people using on Portland Hikers. This is not because the counties are trying to make your life difficult. It is because the formats they use are compatible with GIS programs that are very powerful and more suited to maintaining the most common uses of this data.

I have data for some areas where hikers may be concerned about trespassing. If someone sends me a map of the area of interest I may be able to return a file of property boundaries in .gpx or .kmz format. I will categorize the ownership as Forest Service, WADNR, local government, timber company, or residential. If you want to know one or two specific residential owners you can get it from most county websites.

[Adventure Mapper]

Those who are interested in making custom maps can attend a Community Education class at PCC called "Cartography for Wilderness Exploration" http://www.pcc.edu/schedule/default.cfm ... topicCode=
syllabus http://www.pcc.edu/staff/index.cfm/1470,13542,30,html
example maps http://www.pcc.edu/staff/index.cfm/1470,13544,30,html

[raven]

May I assume that you are the instructor?